Overall piping length in swh systems

[bernard]

Thank you for the reply saniconenergy.

I was actually interested in solar loop only - from the collectors to the storage tank (supply), and from storage tank to collector (return). Only the length of these pipes. Not the length of the pipes from the storage tank to water fixtures (bathroom, kitchen...).
I apologize for not mentioning this on the very beginning.

By the way, what happens if mentioned distance in your reply is larger than 100 feet? A stronger pump is needed?

[inetdog]

Thank you for the reply saniconenergy.

I was actually interested in solar loop only - from the collectors to the storage tank (supply), and from storage tank to collector (return). Only the length of these pipes. Not the length of the pipes from the storage tank to water fixtures (bathroom, kitchen...).
I apologize for not mentioning this on the very beginning.

By the way, what happens if mentioned distance in your reply is larger than 100 feet? A stronger pump is needed?

The biggest thing that happens when you have a run longer than 100 feet is that you waste both energy and water waiting for the heated water to get to the point of use and then letting it cool in the pipe.
A simple recirculating pump takes care of the user experience and water waste but makes the energy waste worse.
There are more sophisticated systems that actually pump on demand from the hot water pipe back into the cold water pipe and then reverse the process to stuff the heated water back into the storage tank when you are done, but their cost and complexity may not make economic and ecological sense either.

[bernard]

Thank you for the information on new systems.

The biggest thing that happens when you have a run longer than 100 feet is that you waste both energy and water waiting for the heated water to get to the point of use and then letting it cool in the pipe.
A simple recirculating pump takes care of the user experience and water waste but makes the energy waste worse.

Isn't this (cooling the water which runs through pipes) something that can be solved with higher thickness of pipe insulation, and/or pipe insulation conductivity? Is it that expensive to increase the insulation thickness and decrease the insulation conductivity (change the insulation material)?

[Solarbyryan]

Can't you just measure it? In places where soft copper is used, add in 10' for each 90 degree turn, in may be less, but I've learned having too much is better as removing soft copper from an attic or other enclosed space is tricky if you plan on reusing it for the same install.

If the enclosed space has alot of obstacles, add a few feet for each of the bends around things like HVAC systems and support beams.

Grab a long rope and mock run it the way you plan, mark where it bends and turns so you know what to buy, where to add length etc. The rope is great for long difficult to measure places. It won't be exact but you'll have an idea and you can decide where to add length. Goock luck!

[saniconenergy]

Thank you for the reply saniconenergy.

I was actually interested in solar loop only - from the collectors to the storage tank (supply), and from storage tank to collector (return). Only the length of these pipes. Not the length of the pipes from the storage tank to water fixtures (bathroom, kitchen...).
I apologize for not mentioning this on the very beginning.

By the way, what happens if mentioned distance in your reply is larger than 100 feet? A stronger pump is needed?

"As quoted by Inetdog, lengthier the pipe is, more the energy losses occur in the Hot Water Loop. Now installing of thicker insulation would also help but to a certain extent. No matter how thick insulation I'm going to install, the bare minimum losses would always be in the range of 10-15%. So this leads us to wonder what to do in this case.

Either install a small POU of 1USG or 3 Liters at the usage point, which should take care of the comfort factor and the moment preheated water would start coming from the centralized solar/ hot water generation system, it would automatically cut off.

Or as mentioned earlier, install a demand driven system. However are experience says that depending on the design, you can easily get the payback of 18-24 months easily if compared with the cost of energy wasted in the recirculation loop."